The invention relates to system for checking defects on the surface of an object such as an original glass plate or a wafer.
An eye-viewing method is conventionally adopted to find out defects on the surface of an object such as a wafer. That is, the method comprises magnifying the surface area to be checked under a microscope to permit observation, or causing an image obtained through the microscope to be displayed on the screen of a CRT. Such method depends largely upon the experience of a checker and lacks a certainty and reliability. Moreover, problems also arise such as limited checking speeds, failure to effect rapid checking, etc.